1. Field of the Invention
The present invention relates to a feeder-lineless traffic system in which a vehicle mounted thereon with an electric storage unit runs on a predetermined pathway such as a railway while receives a power from a ground charging equipment, and to a charging method therefor, and in which a charge control unit is provided on the ground so as to reduce the weight of the vehicle and to simplify the structure of the vehicle.
2. Description of the Related Art
These years, as to a traffic system for running a vehicle on a predetermined railway, there has been proposed a feeder-lineless traffic system utilizing an electric car which can run with no supply of a power from an aerial line. The electric car in the feeder-lineless traffic system is installed therein with an electric storage unit.
For example, Patent Document 1 (Japanese Patent Laid-Open No. 2000-83302) discloses a feeder-lineless traffic system as stated above.
In the traffic system disclosed in the Patent Document 1, a vehicle has a movable power receiver which makes contact with a power feeder provided in a power supply on a station when the vehicle comes to a stop at the power supply, and charging to an onboard electric storage unit is started under instructions by a control unit mounted on the vehicle.
When the power accumulation of the electric storage unit becomes a predetermined value, the onboard control unit delivers a supply stop instruction signal to the power receiver in order to separate the power receiver from the power feeder and to isolate between the power receiver and the electric storage unit. Thus, the on-board control unit controls the power receiving value, a charge voltage, a charging time and the like.
Further, Patent Document 2 (Japanese Patent Laid-Open No. 2006-54958) discloses a feeder-lineless traffic system having such an arrangement that a charging equipment is installed on the ground. This charging equipment comprises a charger composed of a primary core, a primary coil wound on the primary core, a charging power source for feeding a high-frequency power to the primary coil, a communication unit for transmitting charging data (a charging condition of an electric storage unit or the like) transmitted from an onboard communication unit in a vehicle, and a control unit for controlling a charging power, a charging voltage, a charging time and the like in accordance with the thus received charge data.
During charging, a high frequency power is fed from the charging power source to the primary coil, and accordingly, the primary core generates a high frequency magnetic flux which produces an AC power (induced electromotive force) in a secondary coil provided on the vehicle side. The AC power induced in the secondary coil is converted into a DC power by a rectifier provided on the vehicle side, and is accumulated in the onboard electric storage unit.
In the feeder-lineless traffic system disclosed in Patent Document 1, the charge control unit for controlling the power accumulation value and the charging time of the electric storage unit is provided in the vehicle. Thus, the weight of the vehicle is increased, and the structure of the vehicle is complicated if the charge control unit is set up, underfloor of the vehicle. Further, every vehicle requires the charge control unit, and accordingly, the installation costs of the overall traffic system are increased. Further, an onboard charger having a limited size should be used if it is used, the charging time becomes longer, and further, the charging control should be carried out onboard, resulting in a problem of heavily burdening the driver.
Further, in the feeder-lineless traffic system disclosed in the Patent Document 2, since the charge control unit is installed on the ground, the weight of the vehicle can be decreased, and as well, the number of the charge control unit can be reduced so as to offer such an advantage that the installation costs can be reduced. However, this charging system utilizes a noncontact type charging system in which a high frequency power is supplied to a primary coil set up on the ground so as to induce an AC power in a secondary coil. Accordingly, communication units should be provided on both vehicle side and ground side, as stated above, in order to carry out information exchange so as to allow the charge control unit set up on the ground to obtain data as to the charging of the onboard electric storage unit. Accordingly, there would be possibly caused problems of complicating the configuration of components and increasing the costs on both ground side and vehicle side.